Buoy

The tags defined on this page will render ine various nautical charts.

This page defines values for the "seamark:type" tag for buoys and their category attribute tags.

Types

A buoy is a floating object moored to the bottom in a particular place, as an aid to navigation or other specific purposes.

Type

S100 Code

seamark:type

Definition

Example Renderings

Photo

Cardinal Buoy

BOYCAR

buoy_cardinal

A cardinal buoy is used in conjunction with the compass to indicate where the mariner may find the best navigable water. It is placed in one of the four quadrants (North, East, South and West), bounded by inter-cardinal bearings from the point marked.

Installation Buoy

BOYINB

buoy_installation

An installation buoy is a buoy used for loading tankers with gas or oil.

Isolated Danger Buoy

BOYISD

buoy_isolated_danger

A isolated danger buoy is a buoy moored on or above an isolated danger of limited extent, which has navigable water all around it.

Lateral Buoy

BOYLAT

buoy_lateral

A lateral buoy is used to indicate the port or starboard hand side of the route to be followed. They are generally used for well defined channels and are used in conjunction with a conventional direction of buoyage.

A safe water buoy is used to indicate that there is navigable water around the mark.

Special Purpose Buoy

BOYSPP

buoy_special_purpose

A special purpose buoy is primarily used to indicate an area or feature, the nature of which is apparent from reference to a chart, Sailing Directions or Notices to Mariners (UKHO NP 735, 5th Edition). Buoy in general: A buoy whose appearance or purpose is not adequately known.

When top-marks, retro reflectors and/or lights are fitted to these marks, they are encoded as separate objects. Note that such top-marks are encoded as separate "topmark" (TOPMAR) objects). Buoys may also have lights and if such lights are fitted they are encoded as separate "light" (LIGHTS) objects.

Categories

Cardinal Buoys

Cardinal buoys do not have a distinctive shape but are normally pillar or spar. They are always painted in yellow and black horizontal bands and their distinctive double cone top-marks are always black.

Quadrant bounded by the true bearing NW-NE taken from the point of interest it should be passed to the north side of the mark.

black;yellow

2 cones up

East

east

Quadrant bounded by the true bearing NE-SE taken from the point of interest it should be passed to the east side of the mark.

black;yellow;black

2 cones base together

South

south

Quadrant bounded by the true bearing SE-SW taken from the point of interest it should be passed to the south side of the mark.

yellow;black

2 cones down

West

west

Quadrant bounded by the true bearing SW-NW taken from the point of interest it should be passed to the west side of the mark.

yellow;black;yellow

2 cones point together

Installation Buoys

Category (CATINB)

seamark:buoy_installation:category

Definition

Catenary Anchor Leg Mooring

calm

Incorporates a large buoy which remains on the surface at all times and is moored by 4 or more anchors. Mooring hawsers and cargo hoses lead from a turntable on top of the buoy, so that the buoy does not turn as the ship swings to wind and stream.

Single Buoy Mooring

sbm

A mooring structure used by tankers to load and unload in port approaches or in offshore oil and gas fields.

Isolated Danger Buoys

There are no categories of Isolated Danger Buoys. The default colours and topmarks are:

seamark:buoy_isolated_danger:colour

seamark:buoy_isolated_danger:colour_pattern

seamark:topmark:shape

seamark:topmark:colour

black;red;black

horizontal

2 spheres

black

Lateral Buoys

There are two international buoyage regions, A and B, between which lateral marks differ. The buoyage region is encoded using the separate attribute "system" (MARSYS).
Lateral buoys generally have distinctive shapes (can for port-hand, conical for starboard-hand) or may be a pillar or spar with distinctive topmarks. The buoys and their topmarks are always painted in red, green or red & green horizontal bands.